STOCK OPTION AGREEMENT (PROMUS)
                                           
         STOCK OPTION AGREEMENT, dated as of September 1, 1997 (the 
"Agreement"), between PROMUS HOTEL CORPORATION, a Delaware corporation (the 
"Grantee"), and DOUBLETREE CORPORATION, a Delaware corporation (the 
"Grantor").

         WHEREAS, the Grantee, Parent Holding Corp., a Delaware corporation 
("Parent"), and the Grantor are entering into an Agreement and Plan of 
Merger, dated as of the date hereof (the "Merger Agreement"), which provides, 
among other things, for the merger (the "Doubletree Merger") of a subsidiary 
of Parent with and into the Grantor and the merger (the "Promus Merger") of 
another subsidiary of Parent with and into the Grantee, such that the Grantor 
and the Grantee will become wholly-owned subsidiaries of Parent and the 
stockholders of the Grantor and the Grantee will become stockholders of 
Parent (the Doubletree Merger and the Promus Merger collectively, the 
"Mergers");

         WHEREAS, pursuant to a Stock Option Agreement dated as of the date 
hereof between the Grantee and the Grantor, the Grantee has granted the 
Grantor an option to acquire shares of common stock of the Grantee on terms 
that are substantially similar to the terms of this Agreement (the 
"Doubletree Option");

         WHEREAS, as a condition and inducement to their willingness to enter 
into the Merger Agreement and the Doubletree Option, the Grantee and Parent 
have requested that the Grantor grant to the Grantee an option to purchase 
7,898,003 shares of Common Stock, par value $0.01 per share, of the Grantor 
(the "Common Stock"), upon the terms and subject to the conditions hereof; and

         WHEREAS, in order to induce the Grantee to enter into the Merger 
Agreement and grant the Doubletree Option, the Grantor is willing to grant 
the Grantee the requested option.

         NOW, THEREFORE, in consideration of the premises and the mutual 
covenants and agreements set forth herein, the parties hereto agree as 
follows: 

         1.   THE OPTION; EXERCISE; ADJUSTMENTS; PAYMENT OF SPREAD.

              (a)  Contemporaneously herewith the Grantee, Parent and the 
Grantor are entering into the Merger Agreement.  Subject to the other terms 
and conditions set forth herein, the Grantor hereby grants to the Grantee an 
irrevocable option (the "Option") to purchase up to 7,898,003 (as adjusted as 
provided herein) shares of Common Stock (together with the associated 
purchase rights issued with respect thereto pursuant to the Rights Agreement 
dated as of September 1, 1997 between the Grantor and Harris Trust & Savings 
Bank (the "Grantor Rights Plan")) (the "Shares") at a per share cash purchase 
price equal to the lower of (i) $50.00 per Share or (ii) the average closing 
sales price of the Common Stock on the NASDAQ National Market ("NASDAQ") for 
the five consecutive trading days beginning on and including the day that the 
Mergers are publicly announced (as adjusted as provided herein) (such lower 
price being the "Purchase Price").  The Option may be exercised by the 
Grantee, in whole or in part, at any 




time, or from time to time, following the occurrence of one of the events set 
forth in Section 2(c) hereof and prior to the termination of the Option in 
accordance with the terms of this Agreement.

              (b)  In the event the Grantee wishes to exercise the Option, 
the Grantee shall send a written notice to the Grantor (the "Stock Exercise 
Notice") specifying a date (subject to the HSR Act (as defined below)) not 
later than 10 business days and not earlier than the next business day 
following the date such notice is given for the closing of such purchase.  In 
the event of any change in the number of issued and outstanding shares of 
Common Stock by reason of any stock dividend, stock split, split-up, 
reclassification, recapitalization, merger or other change in the corporate 
or capital structure of the Grantor (including the occurrence of a 
Distribution Date under the Grantor Rights Plan), the number of Shares 
subject to this Option and the purchase price per Share shall be 
appropriately adjusted to restore the Grantee to its rights hereunder, 
including its right to purchase Shares representing 19.9% of the capital 
stock of the Grantor entitled to vote generally for the election of the 
directors of the Grantor which is issued and outstanding immediately prior to 
the exercise of the Option at an aggregate purchase price equal to the 
Purchase Price multiplied by 7,898,003 .  In the event that any additional 
shares of Common Stock are issued after the date of this Agreement (other 
than pursuant to an event described in the preceding sentence), the number of 
Shares subject to this Option shall be increased by 19.9% of the number of 
the additional shares of Common Stock so issued (and such additional Shares 
shall have a purchase price per share equal to the Purchase Price).

              (c)  If at any time the Option is then exercisable pursuant to 
the terms of Section 1(a) hereof, the Grantee may elect, in lieu of 
exercising the Option to purchase Shares provided in Section 1(a) hereof, to 
send a written notice to the Grantor (the "Cash Exercise Notice") specifying 
a date not later than 20 business days and not earlier than 10 business days 
following the date such notice is given on which date the Grantor shall pay 
to the Grantee an amount in cash equal to the Spread (as hereinafter defined) 
multiplied by all or such portion of the Shares subject to the Option as 
Grantee shall specify.  As used herein "Spread" shall mean the excess, if 
any, over the Purchase Price of the higher of (x) if applicable, the highest 
price per share of Common Stock (including any brokerage commissions, 
transfer taxes and soliciting dealers' fees) paid by any person in an 
Alternative Transaction (as defined in clause (i), (ii) or (iii) of Section 
7.3(e) of the Merger Agreement) (the "Alternative Purchase Price") or (y) the 
closing sales price of the shares of Common Stock on NASDAQ on the last 
trading day immediately prior to the date of the Cash Exercise Notice (the 
"Closing Price").  If the Alternative Purchase Price includes any property 
other than cash, the Alternative Purchase Price shall be the sum of (i) the 
fixed cash amount, if any, included in the Alternative Purchase Price plus 
(ii) the fair market value of such other property.  If such other property 
consists of securities with an existing public trading market, the average of 
the closing sales prices (or the average of the closing bid and asked prices 
if closing sales prices are unavailable) for such securities in their 
principal public trading market on the five trading days ending five days 
prior to the date of the Cash Exercise Notice shall be deemed to equal the 
fair market value of such property.  If such other property consists of 
something other than cash or securities with an existing public trading 
market and, as of the payment date for the Spread, agreement on the value of 
such other property has not been reached, the Alternative Purchase Price 
shall be deemed to equal the Closing Price.  Upon exercise of the Grantee's 
right to receive cash pursuant to this Section 1(c) and the 

                                     2



payment of such cash to the Grantee, the obligations of the Grantor to 
deliver Shares pursuant to Section 3 shall be terminated with respect to such 
number of Shares for which the Grantee shall have elected to be paid the 
Spread.

         2.   CONDITIONS TO DELIVERY OF SHARES.  The Grantor's obligation to 
deliver Shares upon exercise of the Option is subject only to the conditions 
that:

              (a)  No preliminary or permanent injunction or other order 
issued by any federal or state court of competent jurisdiction in the United 
States prohibiting the delivery of the Shares shall be in effect; and

              (b)  Any applicable waiting periods under the Hart-Scott-Rodino 
Antitrust Improvements Act of 1976 (the "HSR Act") shall have expired or been 
terminated and all other consents, approvals, orders, notifications or 
authorizations, the failure of which to obtain or make would have the effect 
of making the issuance of the Shares illegal (collectively, the "Regulatory 
Approvals") shall have been obtained or made; and

              (c)  (i) a proposal for an Alternative Transaction (as defined 
in the Merger Agreement) involving the Grantor shall have been publicly 
announced prior to the time the Merger Agreement is terminated pursuant to 
the terms thereof (the "Merger Termination Date") and one or more of the 
following events shall have occurred on or after the time of the making of 
such proposal: (A) the requisite vote of the stockholders of the Grantor in 
favor of adoption and approval of the Merger Agreement shall not have been 
obtained at the Doubletree Stockholders' Meeting (as defined in the Merger 
Agreement) or any adjournment or postponement thereof; (B) the Board of 
Directors of the Grantor shall have withdrawn or modified its recommendation 
of the Merger Agreement or the Doubletree Merger or failed to confirm its 
recommendation of the Merger Agreement or the Doubletree Merger to the 
stockholders of the Grantor within ten business days after a written request 
by the Grantee to do so; (C) the Board of Directors of the Grantor shall have 
recommended to the stockholders of the Grantor an Alternative Transaction (as 
defined in the Merger Agreement); (D) a tender offer or exchange offer for 
20% or more of the outstanding shares of Grantor Common Stock shall have been 
commenced (other than by the Grantee or an affiliate of the Grantee) and the 
Board of Directors of the Grantor shall have recommended that the 
stockholders of the Grantor tender their shares in such tender or exchange 
offer; or (E) for any reason the Grantor shall have failed to call and hold 
the Doubletree Stockholders' Meeting (as defined in the Merger Agreement) by 
the Outside Date (as defined in the Merger Agreement); provided, however, 
that the Option may not be exercised if the Grantee is in material breach of 
any of its material representations, warranties, covenants or agreements 
contained in this Agreement or in the Merger Agreement; or (ii) the Merger 
Agreement shall have been terminated by the Grantor pursuant to Section 
7.1(g) of the Merger Agreement.

         3.   THE CLOSING.  

              (a)  Any closing hereunder shall take place on the date 
specified by the Grantee in its Stock Exercise Notice or Cash Exercise 
Notice, as the case may be, at 8:00 A.M., local time, at the offices of 
Latham & Watkins, 633 West Fifth Street, Suite 4000, Los Angeles, 

                                    3



CA 90071, or, if the conditions set forth in Section 2(a) or 2(b) have not 
then been satisfied, on the second business day following the satisfaction of 
such conditions, or at such other time and place as the parties hereto may 
agree (the "Closing Date").  On the Closing Date, (i) in the event of a 
closing pursuant to Section 1(b) hereof, the Grantor will deliver to the 
Grantee a certificate or certificates, duly endorsed (or accompanied by duly 
executed stock powers), representing the Shares in the denominations 
designated by the Grantee in its Stock Exercise Notice and the Grantee will 
purchase such Shares from the Grantor at the price per Share equal to the 
Purchase Price or (ii) in the event of a closing pursuant to Section 1(c) 
hereof, the Grantor will deliver to the Grantee cash in an amount determined 
pursuant to Section 1(c) hereof.  Any payment made by the Grantee to the 
Grantor, or by the Grantor to the Grantee, pursuant to this Agreement shall 
be made by certified or official bank check or by wire transfer of federal 
funds to a bank designated by the party receiving such funds.

              (b)  The certificates representing the Shares may bear an 
appropriate legend relating to the fact that such Shares have not been 
registered under the Securities Act of 1933, as amended (the "Securities 
Act").

         4.   REPRESENTATIONS AND WARRANTIES OF THE GRANTOR.  The Grantor 
represents and warrants to the Grantee that (a) the Grantor is a corporation 
duly organized, validly existing and in good standing under the laws of the 
State of Delaware and has the requisite corporate power and authority to 
enter into and perform this Agreement; (b) the execution and delivery of this 
Agreement by the Grantor and the consummation by it of the transactions 
contemplated hereby have been duly authorized by the Board of Directors of 
the Grantor and this Agreement has been duly executed and delivered by a duly 
authorized officer of the Grantor and constitutes a valid and binding 
obligation of the Grantor, enforceable in accordance with its terms, subject 
to bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium 
and similar laws of general applicability relating to or affecting creditors' 
rights and to general equity principles; (c) the Grantor has taken all 
necessary corporate action to authorize and reserve the Shares issuable upon 
exercise of the Option and the Shares, when issued and delivered by the 
Grantor upon exercise of the Option, will be duly authorized, validly issued, 
fully paid and non-assessable and free of preemptive rights; (d) except as 
otherwise required by the HSR Act and other than any filings required under 
the blue sky laws of any states or by NASDAQ, the execution and delivery of 
this Agreement by the Grantor and the issuance of Shares upon exercise of the 
Option do not require the consent, waiver, approval or authorization of or 
any filing with any person or public authority and will not violate, result 
in a breach of or the acceleration of any obligation under, or constitute a 
default under, any provision of any charter or by-law, indenture, mortgage, 
lien, lease, agreement, contract, instrument, order, law, rule, regulation, 
judgment, ordinance, or decree, or restriction by which the Grantor or any of 
its subsidiaries or any of their respective properties or assets is bound; 
(e) no "fair price", "moratorium", "control share acquisition" or other form 
of antitakeover statute or regulation (including, without limitation, the 
restrictions on "business combinations" set forth in Section 203 of the 
Delaware General Corporation Law) is or shall be applicable to the 
acquisition of Shares pursuant to this Agreement (and the Board of Directors 
of Grantor has taken all action to approve the acquisition of the Shares to 
the extent necessary to avoid such application) and (f)  the Grantor has 
taken all corporate action necessary so that the grant and any 

                                    4



subsequent exercise of the Option by the Grantee will not result in the 
separation or exercisability of rights under the Grantor Rights Plan..

         5.   REPRESENTATIONS AND WARRANTIES OF THE GRANTEE.  The Grantee 
represents and warrants to the Grantor that (a) the execution and delivery of 
this Agreement by the Grantee and the consummation by it of the transactions 
contemplated hereby have been duly authorized by all necessary corporate 
action on the part of the Grantee and this Agreement has been duly executed 
and delivered by a duly authorized officer of the Grantee and will constitute 
a valid and binding obligation of Grantee; and (b) the Grantee is acquiring 
the Option after the Grantee has been afforded the opportunity to obtain, and 
has obtained, sufficient information regarding the Grantor to make an 
informed investment decision with respect to the Grantee's purchase of the 
Shares issuable upon exercise thereof, and, if and when the Grantee exercises 
the Option, it will be acquiring the Shares issuable upon the exercise 
thereof for its own account and not with a view to distribution or resale in 
any manner which would be in violation of the Securities Act.

         6.   QUOTATION OF SHARES; HSR ACT FILINGS; REGULATORY APPROVALS. 
Subject to applicable law and the rules and regulations of NASDAQ, the 
Grantor will promptly file an application to have the Shares quoted on NASDAQ 
and will use its best efforts to obtain approval of such quotation and to 
file all necessary filings by the Grantor under the HSR Act; provided, 
however, that if the Grantor is unable to effect such quotation on NASDAQ by 
the Closing Date, the Grantor will nevertheless be obligated to deliver the 
Shares upon the Closing Date.  Each of the parties hereto will use its best 
efforts to obtain consents of all third parties and all Regulatory Approvals, 
if any, necessary to the consummation of the transactions contemplated.

         7.   REPURCHASE OF SHARES; SALE OF SHARES.  If a Change in Control 
Event has not occurred prior to the first anniversary date of the Merger 
Termination Date, then beginning on such anniversary date, the Grantor shall 
have the right to purchase (the "Repurchase Right") all, but not less than 
all, of the Shares then beneficially owned by the Grantee or any of its 
affiliates at a price per share equal to the greater of (i) the Purchase 
Price, or (ii) the average of the closing sales prices for shares of Common 
Stock on the twenty trading days ending five days prior to the date the 
Grantor gives written notice of its intention to exercise the Repurchase 
Right.  If the Grantor does not exercise the Repurchase Right within thirty 
days following the first anniversary of the Merger Termination Date, the 
Repurchase Right terminates.  In the event the Grantor wishes to exercise the 
Repurchase Right, the Grantor shall send a written notice to the Grantee 
specifying a date (not later than 10 business days and not earlier than the 
next business day following the date such notice is given) for the closing of 
such purchase.  For purposes of the Agreement, a "Change in Control Event" 
shall be deemed to have occurred if (i) any person or group has a acquired 
beneficial ownership of more than fifty percent (excluding the Shares) of the 
outstanding shares of Common Stock or (ii) the Grantor shall have entered 
into an agreement, including without limitation an agreement in principle, 
providing for (x) a merger or other business combination involving the 
Grantor in which the Grantor's stockholders do not own a majority of the 
outstanding capital stock of the entity surviving such merger or business 
combination immediately following such transaction or (y) the acquisition of 
20% or more of the assets of the Grantor and its subsidiaries, taken as a 
whole.

                                     5




         8.   REGISTRATION RIGHTS.

              (a)  In the event that the Grantee shall desire to sell any of 
the Shares within two years after the purchase of such Shares pursuant 
hereto, and such sale requires, in the opinion of counsel to the Grantee, 
which opinion shall be reasonably satisfactory to the Grantor and its 
counsel, registration of such Shares under the Securities Act, the Grantor 
will cooperate with the Grantee and any underwriters in registering such 
Shares for resale, including, without limitation, promptly filing a 
registration statement which complies with the requirements of applicable 
federal and state securities laws, entering into an underwriting agreement 
with such underwriters upon such terms and conditions as are customarily 
contained in underwriting agreements with respect to secondary distributions; 
provided that the Grantor shall not be required to have declared effective 
more than two registration statements hereunder and shall be entitled to 
delay the filing or effectiveness of any registration statement for up to 120 
days if the offering would, in the judgment of the Board of Directors of the 
Grantor, require premature disclosure of any material corporate development 
or otherwise interfere with or adversely affect any pending or proposed 
offering of securities of the Grantor or any other material transaction 
involving the Grantor.

              (b)  If the Common Stock is registered pursuant to the 
provisions of this Section 8, the Grantor agrees (i) to furnish copies of the 
registration statement and the prospectus relating to the Shares covered 
thereby in such numbers as the Grantee may from time to time reasonably 
request and (ii) if any event shall occur as a result of which it becomes 
necessary to amend or supplement any registration statement or prospectus, to 
prepare and file under the applicable securities laws such amendments and 
supplements as may be necessary to keep effective for at least 90 days a 
prospectus covering the Common Stock meeting the requirements of such 
securities laws, and to furnish the Grantee such numbers of copies of the 
registration statement and prospectus as amended or supplemented as may 
reasonably be requested.  The Grantor shall bear the cost of the 
registration, including, but not limited to, all registration and filing 
fees, printing expenses, and fees and disbursements of counsel and 
accountants for the Grantor, except that the Grantee shall pay the fees and 
disbursements of its counsel, the underwriting fees and selling commissions 
applicable to the shares of Common Stock sold by the Grantee.  The Grantor 
shall indemnify and hold harmless Grantee, its affiliates and its officers, 
directors and controlling persons from and against any and all losses, 
claims, damages, liabilities and expenses arising out of or based upon any 
statements contained or incorporated by reference in, and omissions or 
alleged omissions from, each registration statement filed pursuant to this 
paragraph; provided, however, that this provision does not apply to any loss, 
liability, claim, damage or expense to the extent it arises out of any untrue 
statement or omission made in reliance upon and in conformity with written 
information furnished to the Grantor by the Grantee, its affiliates and its 
officers expressly for use in any registration statement (or any amendment 
thereto) or any preliminary prospectus filed pursuant to this paragraph.  The 
Grantor shall also indemnify and hold harmless each underwriter and each 
person who controls any underwriter within the meaning of either the 
Securities Act or the Securities Exchange Act of 1934, as amended, against 
any and all losses, claims, damages, liabilities and expenses arising out of 
or based upon any statements contained or incorporated by reference in, and 
omissions or alleged omissions from, each registration statement filed 
pursuant 

                                    6



to this paragraph; provided, however, that this provision does not apply to 
any loss, liability, claim, damage or expense to the extent it arises out of 
any untrue statement or omission made in reliance upon and in conformity with 
written information furnished to the Grantor by the underwriters expressly 
for use in any registration statement (or any amendment thereto) or any 
preliminary prospectus filed pursuant to this paragraph.

         9.   PROFIT LIMITATION.  

              (a)  Notwithstanding any other provision of this Agreement, in 
no event shall the Grantee's Total Profit (as hereinafter defined) exceed $65 
million and, if it does exceed such amount, the Grantee, at its sole 
election, shall, within five business days, either (a) deliver to the Grantor 
for cancellation Shares (valued, for the purposes of this Section 9(a), at 
the average closing sales price of the Common Stock on NASDAQ for the twenty 
consecutive trading days preceding the day on which the Grantee's Total 
Profit exceeds $65 million) previously purchased by the Grantee, (b) pay cash 
or other consideration to the Grantor or (c) undertake any combination 
thereof, so that the Grantee's Total Profit shall not exceed $65 million 
after taking into account the foregoing actions.

              (b)  As used herein, the term "Total Profit" shall mean the 
aggregate amount (before taxes) of the following: (i) the amount of cash 
received by the Grantee pursuant to Section 7.3(b) of the Merger Agreement 
and Section 1(c) hereof, (ii)(x) the net cash amount received by the Grantee 
pursuant to the Grantor's repurchase of Shares pursuant to Section 7 hereof, 
less (y) the Grantee's purchase price for such Shares, and (iii)(x) the 
amount received by the Grantee pursuant to the sale of Shares (or any other 
securities into which such Shares are converted or exchanged), less (y) the 
Grantee's purchase price for such Shares.

         10.  EXPENSES.  Each party hereto shall pay its own expenses 
incurred in connection with this Agreement, except as otherwise specifically 
provided herein.

         11.  SPECIFIC PERFORMANCE.  The Grantor acknowledges that if the 
Grantor fails to perform any of its obligations under this Agreement 
immediate and irreparable harm or injury would be caused to the Grantee for 
which money damages would not be an adequate remedy.  In such event, the 
Grantor agrees that the Grantee shall have the right, in addition to any 
other rights it may have, to specific performance of this Agreement.  
Accordingly, if the Grantee should institute an action or proceeding seeking 
specific enforcement of the provisions hereof, the Grantor hereby waives the 
claim or defense that the Grantee has an adequate remedy at law and hereby 
agrees not to assert in any such action or proceeding the claim or defense 
that such a remedy at law exists.  The Grantor further agrees to waive any 
requirements for the securing or posting of any bond in connection with 
obtaining any such equitable relief.

         12.  NOTICE.  All notices, requests, demands and other 
communications hereunder shall be deemed to have been duly given and made if 
in writing and if served by personal delivery upon the party for whom it is 
intended or delivered by registered or certified mail, return receipt 
requested, or if sent by facsimile transmission, upon receipt of oral 
confirmation that such transmission has been received, to the person at the 
address set forth 

                                    7



below, or such other address as may be designated in writing hereafter, in 
the same manner, by such person:

         If to the Grantee:

         Promus Hotel Corporation
         755 Crossover Lane
         Memphis, TN  38117
         Attn:  Raymond E. Schultz
         Telecopy: (901) 374-5636

         With a copy to:

         Latham & Watkins
         633 West Fifth Street, Suite 4000
         Los Angeles, California 90071-2007
         Attn: John M. Newell, Esq.
         Telecopy: (213) 891-8763

         If to the Grantor:

         Doubletree Corporation
         North 44th Street, Suite 700
         Phoenix, AZ  85008
         Attn:  Richard M. Kelleher
         Telecopy: (602) 220-6753

         With a copy to:

         Dewey Ballantine
         1301 Avenue of the Americas
         New York, NY 10019-6092
         Attn:  William J. Phillips, Esq.
         Telecopy: (212) 295-6333

         13.  PARTIES IN INTEREST.  This Agreement shall inure to the benefit 
of and be binding upon the parties named herein and their respective 
permitted successors and assigns; provided, however, that such successor in 
interest or assigns shall agree to be bound by the provisions of this 
Agreement.  Except as set forth in Section 8, nothing in this Agreement, 
express or implied, is intended to confer upon any person other than the 
Grantor or the Grantee, or their successors or assigns, any rights or 
remedies under or by reason of this Agreement.

         14.  ENTIRE AGREEMENT; AMENDMENTS.  This Agreement, together with 
the Merger Agreement and the other documents referred to therein, contains 
the entire agreement between the parties hereto with respect to the subject 
matter hereof and supersedes all prior and contemporaneous agreements and 
understandings, oral or written, with respect to such transactions.  This 
Agreement may not be changed, amended or modified orally, but may be changed 
only by an agreement in writing signed by the party against whom any waiver, 
change, amendment, modification or discharge may be sought.

                                    8



         15.  ASSIGNMENT.  No party to this Agreement may assign any of its 
rights or obligations under this Agreement without the prior written consent 
of the other party hereto, except that the Grantee may assign its rights and 
obligations hereunder to any of its direct or indirect wholly owned 
subsidiaries, but no such transfer shall relieve the Grantee of its 
obligations hereunder if such transferee does not perform such obligations.  
Any assignment made in violation of this Section 15 shall be void.

         16.  HEADINGS.  The section headings herein are for convenience only 
and shall not affect the construction of this Agreement.

         17.  COUNTERPARTS.  This Agreement may be executed in any number of 
counterparts, each of which, when executed, shall be deemed to be an original 
and all of which together shall constitute one and the same document. 

         18.  GOVERNING LAW.  This Agreement shall be governed by and 
construed in accordance with the laws of the State of Delaware (regardless of 
the laws that might otherwise govern under applicable Delaware principles of 
conflicts of law).

         19.  TERMINATION.  The right to exercise the Option granted pursuant 
to this Agreement shall terminate at the earlier of (i) the Effective Time 
(as defined in the Merger Agreement), (ii) the date on which the Grantee 
realizes a Total Profit of $65 million, (iii) the date on which the Merger 
Agreement is terminated; provided that the Option is not exercisable at such 
time and does not become exercisable simultaneous with such termination and 
(iv) 90 days after the date the Option becomes exercisable (the date referred 
to in clause (iv) being hereinafter referred to as the "Option Termination 
Date"); provided that, if the Option cannot be exercised or the Shares cannot 
be delivered to the Grantee upon such exercise because the conditions set 
forth in Section 2(a) or Section 2(b) hereof have not yet been satisfied, the 
Option Termination Date shall be extended until thirty days after such 
impediment to exercise has been removed.

         All representations and warranties contained in this Agreement shall 
survive delivery of and payment for the Shares.

         20.  SEVERABILITY.  If any term, provision, covenant or restriction 
of this Agreement is held by a court of competent jurisdiction to be invalid, 
void or unenforceable, the remainder of the terms, provisions, covenants and 
restrictions of this Agreement shall remain in full force and effect and 
shall in no way be affected, impaired or invalidated.

         21.  PUBLIC ANNOUNCEMENT.  The Grantee will consult with the Grantor 
and the Grantor will consult with the Grantee before issuing any press 
release with respect to the initial announcement of this Agreement, the 
Option or the transactions contemplated hereby and neither party shall issue 
any such press release prior to such consultation except as may be required 
by law. 

                                    9



              Signature Page for Stock Option Agreement (Promus)

          IN WITNESS WHEREOF, the Grantee and the Grantor have caused this 
Agreement to be signed by their respective duly authorized officers as of the 
date first written above.

                                           DOUBLETREE CORPORATION



                                           /S/ Richard M. Kelleher
                                   ------------------------------------------
                                    By:  Richard M. Kelleher
                                   Its: President and Chief Executive Officer
     


                                          PROMUS HOTEL CORPORATION
     


                                          /S/ Raymond E. Schultz
                                   ------------------------------------------
                                     By:  Raymond E. Schultz
                                    Its:  President and Chief Executive Officer
     

                                    S-1